1984 Dixie ski boat floor restoration

[tfret]

I will be installing a new floor in the spring that will require a couple of sheets of marine plywood. I know new treated lumber is typically very "wet" when first purchased and will need to dry out before applying reisen. I considered buying it now so it would have all winter to dry out. But I'm afraid it will warp if I stand it in my garage. I don't really have the space to lay it flat anywhere. I do have a covered patio I could lay it on but I've been told the wood could pull moisture from the concrete, so I don't know if thats a good idea or not. What do you think?

 

[jmeny]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

If you're going to seal it anyways you might want to save the money and get some standard exterior grade plywood instead of the marine, the arauco stuff is pretty nice. If you lean it up against a wall in your garage to dry I don't think it would warp noticably (I didn't have a problem doing this), but others might have better suggestions.

 

[JDA1975]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

if you decide to lay it flat on your covered patio, don't place it directly on the ground, get some 2x4 and place it at 2' centers to hold the wood, between each successive board add another row of 2x4, to allow airflow so it dries evenly...if you lean it against a wall you want air between them also, and try to keep them as vertical as possible, the larger the angle of rest, the more likely to warp!

 

[tfret]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

I looked at the exterior plywood at both big box hardward ware stores and frankly speaking, it looks like crap. The edges show lots of voids, the panels are full of large nots, I don't know if I would build a dog house with that stuff, much less my boat floor. Granted the marine board is expensive, but I want to do this right. We have to store the boat outdoors year round so it gets lots of moisture in it, despite haveing a good cover. I actually plan to glass both sides and edges of the wood to ensure it doesn't rot again as long as I own it. I may buy the wood now and stand it in my basement against the wall, and turn it around every couple of weeks so the sides dry evenly. Hopefully this will prevent warping.

 

[Woodonglass]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

Go to a Quality Lumber Yard and Askto look at their Underlayment Plywood or even better yet some MDO Plywood. Both are 100% waterproof glue and minimal voids. You'll save at least 50% over the Marine grade.

 

[oops!]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

very good discussion here...

http://forums.iboats.com/showthread.php?t=231989&highlight=drying+plywood

 

[Bondo]

Re: Marine plywood, best way to dry without warping?

Re: Marine plywood, best way to dry without warping?

But I'm afraid it will warp if I stand it in my garage. I don't really have the space to lay it flat anywhere.

Ayuh,.... Stand it tight against the wall, 'n Screw it....

A couple of 2x, from stud to stud to stud will hold it Flat...
Or atleast as flat as it needs to be...

Screw it up tight with deck screws...

 

[tfret]

MDO VS marine plywood

MDO VS marine plywood

I'm doing a bunch of research on replacing my deck and have seen both of these materials recommended. I talked with a local lumber supplier (not a big box retailer but an actual lumber yard) and the guy told me MDO was designed for outdoor signs, like parks etc.. and was water proof and perfect for boat floors. I just wanted to get a few opinions from folks that may have used one or the other or both for that matter, and see what people think about this. Thanks for the feedback.

 

[Woodonglass]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Yep, MDO is GREAT STUFF for Decks. I'd still recommend scuffing the top surface with 60 grit and then laying a couple of layers of CSM to ensure great waterproofing. This should help your decision making...

http://www.plumcreek.com/Portals/0/downloads/productInfo/MDO.pdf

 

[island mike]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Mdo good stuff.
Use it.

 

[kfa4303]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Hi guys. Should the MDO be treated the same way you prep would exterior grade plywood (i.e. use epoxy or polyester resin & fiberglass to waterproof), or do you have to use a particular method. Thanks.

 

[tfret]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Ok, it sounds like MDO is the way to go. It even costs less which is an added bonus. I still plan to glass the top as Woodonglass suggested. But I have the same question as kfa4303, do I still need to epoxy or resin coat the bottom and edges good?

 

[Woodonglass]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Depends on the kind you get. If you get the MDO that is finished on both sides. (Resin coated) then I don't think you need to worry about the bottom side of the the deck. If you just get single sided then, I'd put the finished side down, and use the resin and glass on the top side. Edges Absolutely!!! Topside I already covered. MDO is used for painted roadsigns and all they do is paint the edeges and some of those signs last 30 years! It's some great exterior grade material.

 

[tfret]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Resin coated side down and don't worry about coating it. Sounds good. I'll coat the edges well and glass the top. Thanks guys. I plan on posting a bunch of photos to start a formal restoration thread. But I just wanted to get most of my questions answered up front. Thanks again to everyone for making the DIY boater life soooo much easier!

 

[Gun Dog]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

I've been using MDO in exterior sign making for many years. Even when design routed and lettered it holds up great. One exterior sign I did sits along a road exposed to road salt and the works. It still looks great after 10 years. Seal all areas that have been cut or routed. The coated surface is thin and if you are to rough with sanding you will blow right through. It's smooth enough to just hit it with a 220 grit.

 

[tfret]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

The original deck was 1/2". I'm wondering if I glass the top really well if I can get by with 3/8". I'm trying to get the weight down and it all adds up. I think the glass really adds all lot of strength. My old floor was glassed on top and only felt soft in a few places but turns out it was all rotton. The soft areas basically had no wood left, just black mush.

 

[ezmobee]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

The original deck was 1/2". I'm wondering if I glass the top really well if I can get by with 3/8".

I wouldn't.

 

[Woodonglass]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

+1^^^^ 1/2" minimum. You'll be adding 10lbs additional weight.

 

[island mike]

Re: MDO VS marine plywood

Re: MDO VS marine plywood

Be carefull if you are not going to glass the bottom part,if you scratch it slightly,That spot will not be sealed anymore.I would glass it just to make sure.
About the edges,I dont know your level of fiberglassing experience but again to be sure,fiberglass does not like sharp edges,Round the edges so that the mat will adhere well without bubbles..or you could just seal it with resin.
Good luck.
And ahh we likes pics.

 

[tfret]

Re: MDO VS marine plywood

Re: MDO VS marine plywood



OK. I just got home with two sheets of MDO, still in the back of the mini van. I asked about the resin coating, is it one side or both? Nobody seemed to know. They called the manufacturer and the guy there wasn't sure. SO, here I am at home, lumber still in the car, and I need some advice. Both sides are paper coated with what looks like brown paper bag material. I'm guessing I'm going to need to resin coat the bottom side really well before putting it down, where I had hoped to purchase material already coated to allow me to skip that step. Oh well. That's what I get for thinking I'm going to get ahead of the game! So please confirm for me that is what I need to do. Concerning the post asking about my fiberglassing experience: Zero. So this will be a big learning curve for me that will require many posts with lots of rookie questions. (I'm not even sure if I up loaded the pics right, we'll see) But I'm going to do it, and plan to do it right.